The mTOR pathway controls phosphorylation of BRAF at T401.

Publisher: BioMed Central Country of Publication: England NLM ID: 101170464 Publication Model: Electronic Cited Medium: Internet ISSN: 1478-811X (Electronic) Linking ISSN: 1478811X NLM ISO Abbreviation: Cell Commun Signal Subsets: MEDLINE

Original Publication: [London] : BioMed Central, c2003-

TOR Serine-Threonine Kinases*/metabolism ; Proto-Oncogene Proteins B-raf*/metabolism ; Proto-Oncogene Proteins B-raf*/genetics; Phosphorylation/drug effects ; Humans ; Animals ; Mice ; Signal Transduction/drug effects ; HEK293 Cells ; Pyrimidinones/pharmacology ; Mechanistic Target of Rapamycin Complex 1/metabolism ; Pyridones/pharmacology ; Naphthyridines

BRAF serves as a gatekeeper of the RAS/RAF/MEK/ERK pathway, which plays a crucial role in homeostasis. Since aberrant signalling of this axis contributes to cancer and other diseases, it is tightly regulated by crosstalk with the PI3K/AKT/mTOR pathway and ERK mediated feedback loops. For example, ERK limits BRAF signalling through phosphorylation of multiple residues. One of these, T401, is widely considered as an ERK substrate following acute pathway activation by growth factors. Here, we demonstrate that prominent T401 phosphorylation (pT401) of endogenous BRAF is already observed in the absence of acute stimulation in various cell lines of murine and human origin. Importantly, the BRAF/RAF1 inhibitor naporafenib, the MEK inhibitor trametinib and the ERK inhibitor ulixertinib failed to reduce pT401 levels in these settings, supporting an alternative ERK-independent pathway to T401 phosphorylation. In contrast, the mTOR inhibitor torin1 and the dual-specific PI3K/mTOR inhibitor dactolisib significantly suppressed pT401 levels in all investigated cell types, in both a time and concentration dependent manner. Conversely, genetic mTOR pathway activation by oncogenic RHEB (Q64L) and mTOR (S2215Y and R2505P) mutants substantially increased pT401, an effect that was reverted by dactolisib and torin1 but not by trametinib. We also show that shRNAmir mediated depletion of the mTORC1 complex subunit Raptor significantly enhanced the suppression of T401 phosphorylation by a low torin1 dose, while knockdown of the mTORC2 complex subunit Rictor was less effective. Using mass spectrometry, we provide further evidence that torin1 suppresses the phosphorylation of T401, S405 and S409 but not of other important regulatory phosphorylation sites such as S446, S729 and S750. In summary, our data identify the mTOR axis and its inhibitors of (pre)clinical relevance as novel modulators of BRAF phosphorylation at T401.
(© 2024. The Author(s).)

Genes (Basel). 2020 Sep 04;11(9):. (PMID: 32899613)
Sci Signal. 2010 Jan 12;3(104):ra3. (PMID: 20068231)
Biochem Soc Trans. 2021 Feb 26;49(1):237-251. (PMID: 33367512)
Nat Biotechnol. 2008 Dec;26(12):1367-72. (PMID: 19029910)
Cell. 2022 May 26;185(11):1814-1836. (PMID: 35580586)
Cell Rep. 2019 Oct 15;29(3):573-588.e7. (PMID: 31618628)
Proc Natl Acad Sci U S A. 2010 Dec 21;107(51):22314-9. (PMID: 21135229)
Br J Cancer. 2024 Apr;130(7):1119-1130. (PMID: 38341510)
Oncotarget. 2016 May 3;7(18):26628-52. (PMID: 27034005)
Mol Cell. 2015 Jun 18;58(6):977-88. (PMID: 26028537)
Nat Rev Mol Cell Biol. 2020 Oct;21(10):607-632. (PMID: 32576977)
Genes Dev. 2012 Dec 1;26(23):2561-6. (PMID: 23152448)
Annu Rev Biochem. 2024 Aug;93(1):289-316. (PMID: 38316136)
Nature. 2016 May 25;534(7605):55-62. (PMID: 27251275)
Nucleic Acids Res. 2015 Jan;43(Database issue):D512-20. (PMID: 25514926)
Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):11022-7. (PMID: 19541618)
Development. 2020 Dec 23;147(24):. (PMID: 33144396)
MicroPubl Biol. 2024 Mar 27;2024:. (PMID: 38605723)
Oncogene. 2008 Sep 25;27(43):5729-40. (PMID: 18521078)
Science. 2024 Jun 7;384(6700):eadk0850. (PMID: 38843329)
J Biol Chem. 2000 Sep 1;275(35):27354-9. (PMID: 10869359)
Mol Cell. 2006 Oct 20;24(2):185-97. (PMID: 17052453)
EMBO J. 2012 May 30;31(11):2629-47. (PMID: 22510884)
Front Immunol. 2019 Dec 20;10:2952. (PMID: 31921197)
Cancer Res. 2021 Dec 15;81(24):6074-6077. (PMID: 34911779)
Nat Commun. 2022 Dec 8;13(1):7578. (PMID: 36481721)
Cell Signal. 2016 Jun;28(6):561-71. (PMID: 26898828)
Commun Biol. 2018 Apr 5;1:29. (PMID: 30271915)
Sci Signal. 2023 Aug 29;16(800):eabq4355. (PMID: 37643243)
Nat Commun. 2020 Jan 24;11(1):499. (PMID: 31980649)
Nat Commun. 2019 Apr 23;10(1):1870. (PMID: 31015455)
Oncogene. 2013 Jun 13;32(24):2917-2926. (PMID: 22797077)
FEBS Lett. 2017 Sep;591(17):2607-2615. (PMID: 28675784)
Int J Mol Sci. 2020 Dec 22;22(1):. (PMID: 33375117)
Amino Acids. 2010 Jan;38(1):223-8. (PMID: 19145465)
J Immunol. 2013 Mar 1;190(5):1927-35. (PMID: 23359496)
J Biol Chem. 2005 Oct 28;280(43):35829-35. (PMID: 16109716)
iScience. 2024 Feb 19;27(3):109302. (PMID: 38450154)
Hum Mol Genet. 2002 Mar 1;11(5):525-34. (PMID: 11875047)
Nat Protoc. 2016 Dec;11(12):2301-2319. (PMID: 27809316)
Nat Struct Mol Biol. 2022 Oct;29(10):958-960. (PMID: 36192652)
Oncogene. 2010 May 6;29(18):2746-52. (PMID: 20190810)
Oncogene. 2018 Jun;37(24):3183-3199. (PMID: 29540830)
Proteomics. 2007 Jan;7(2):206-14. (PMID: 17163575)
Nat Methods. 2009 May;6(5):359-62. (PMID: 19377485)
EMBO J. 1999 Apr 15;18(8):2137-48. (PMID: 10205168)
Mol Cell Biol. 2006 Mar;26(6):2262-72. (PMID: 16508002)
Oncogene. 2003 Dec 4;22(55):8823-34. (PMID: 14654779)
Genes Dev. 2012 Nov 15;26(22):2524-35. (PMID: 23154983)
J Biol Chem. 2008 Jan 4;283(1):100-109. (PMID: 17971449)
Cancer Discov. 2014 May;4(5):554-63. (PMID: 24631838)
Mol Cell Biol. 2010 Feb;30(3):806-19. (PMID: 19933846)
J Clin Endocrinol Metab. 2012 Jul;97(7):E1139-49. (PMID: 22549934)
Proc Natl Acad Sci U S A. 1999 Apr 13;96(8):4438-42. (PMID: 10200280)
EMBO J. 2017 Mar 1;36(5):646-663. (PMID: 28093501)
Curr Opin Pharmacol. 2005 Aug;5(4):418-23. (PMID: 15955739)
J Biol Chem. 2009 Mar 20;284(12):8023-32. (PMID: 19150980)
Sci Adv. 2023 Sep;9(35):eade7486. (PMID: 37656784)

310030E_184433 Swiss National Science Foundation SNF; BR3662/4-1 Deutsche Forschungsgemeinschaft; B310-JF-LOGGIC-MDE Deutschen Konsortium für Translationale Krebsforschung

EC 2.7.11.1 (TOR Serine-Threonine Kinases)
EC 2.7.11.1 (Proto-Oncogene Proteins B-raf)
0 (Pyrimidinones)
0 (1-(4-(4-propionylpiperazin-1-yl)-3-(trifluoromethyl)phenyl)-9-(quinolin-3-yl)benzo(h)(1,6)naphthyridin-2(1H)-one)
EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 1)
33E86K87QN (trametinib)
0 (Pyridones)
0 (Naphthyridines)

Date Created: 20240902 Date Completed: 20240903 Latest Revision: 20240905

20240905

PMC11370054

10.1186/s12964-024-01808-2

39223665